Wearing a light brown coat and brown hat, boots and bag, Ms Markle walked arm-in-arm with fiance Prince Harry as they made the short journey from Sandringham House to St Mary Magdalene Church.

She seemed at ease as they smiled and chatted as they walked alongside William and Kate, who is pregnant with her third child.

The Queen arrived in a car and joined the group from the house which also included the Duke of Edinburgh and the Prince of Wales.

Hundreds of well-wishers turned out to catch a glimpse of the royal family, with some calling out “Merry Christmas” as they walked past.

The Duchess of Cambridge (left) and Meghan Markle arriving to attend the Christmas Day service. Picture: Joe Giddens/PA Wire

American couple Mike Metz and Ashley Millican, both aged 20 and visiting their UK-based relative from Wisconsin, were waiting to see the Queen, Prince Harry and his fiancee attend St Mary Magdalene Church on the Queen’s Sandringham Estate for the Christmas Day service when Mike got on one knee.

Asked by Sky News royal correspondent Rhiannon Mills why it was so important for them to come and see the royals on Christmas morning, Mr Metz got on one knee and said: “I want to spend the rest of my Christmases with you Ashley, so I don’t know if you want to marry me?”

Putting her hand to her mouth and fighting back tears, she replied: “Yes. Oh my God.”

Taking the ring from the little white box and weeping, she said: “Yes, yes, yes.”

The crowds lining the road shouted Christmas greetings as they passed by.

Those waiting to see the royal family arrive at church included:

■ Phil Longwell 46, from Wells: “This is the first time that I have actually come to Sandringham on Christmas. I’ve never actually seen the Queen and living locally I thought I would treat myself to it and I got up early, did all the vegetables and came out. I have been waiting out here since 7.30am but I didn’t have to come far.”

■ Fawn Peralta, 35, Washington state, USAF Lakenheath: “We have just come to wish all the royal family a merry Christmas. I’d love to wish Harry congratulations on the engagement and I’m really hoping to see little George and Charlotte.

(Left-right) The Duchess of Cornwall, the Prince of Wales and Lady Sarah Chatto arriving to attend an early Christmas Day church service at St Mary Magdalene Church in Sandringham, Norfolk. PRESS ASSOCIATION Photo. Picture date: Monday December 25, 2017. Photo credit should read: Joe Giddens/PA Wire

“It will be amazing to see Kate’s little bump and wish them well.”

■ Ron Hatfield, 62, from Ohio: “We are over here visiting my son who is in the US airforce. We have come from Lakenheath. I have never seen a president so to see the royal family will be something else.”

Fawn Peralta from USAF Lakenheath waits with her family to see the Royals at Sandringham Church. Photo: Marc Betts

Phil Longwell from Wells waits to see the Royals at Sandringham Church. Photo: Marc Betts

Ron Hatfield from Ohio, USA, waits to see the Royals at Sandringham Church. Photo: Marc Betts